Depending on the tire sizes selected, the rolling diameter could be very close or very different. 700c is ISO622, 26" MTB are generally ISO559. If you put a 23x622 tire on front, it will have a rolling diameter of 668mm; a 53x559 on back will provide: 665mm - practically the same.

There have been many bikes manufactured with different size wheels front and rear; plan to adjust handle bars and saddle to suit.

(02-07-2012, 08:24 PM)nfmisso Wrote: Try it; if it works for you, no issues. If not, no loss in trying.

Depending on the tire sizes selected, the rolling diameter could be very close or very different. 700c is ISO622, 26" MTB are generally ISO559. If you put a 23x622 tire on front, it will have a rolling diameter of 668mm; a 53x559 on back will provide: 665mm - practically the same.

There have been many bikes manufactured with different size wheels front and rear; plan to adjust handle bars and saddle to suit.

Both wheels already have relatively new tyres - sizes: Front 622-37=696 and Rear 559-41=641, overall difference = 55mm..
I also have a 26" front wheel with roller brake, but there is no special braze-on on the forks for the roller brake...
Also no attachment points for Disk brakes.
Are there any adapters I could get for the forks to convert to either roller or disk brakes?
I am assuming the v brakes on my 700c forks would not reach 26" rims...

Forks for disc brakes have to be designed to withstand the higher forces, so no adapters exist (even if they would exist they must never be used). I'm not sure but I guess this would also hold for roller brakes, but maybe the engineers here can comment. The point where the force acts on the fork blades is much different for disc and rim breaks.

The V-brake bosses on a fork for 700c rims will actually sit almost above the 26" rim, so no luck there. You might be able to use Mafac centre pull brakes (bosses might be too far apart, though), however performance of those is... not good, no precious.

So: try your setup (carefully), if it does not work you have to play the replacing game: either the fork + front wheel or the rear wheel have to be changed. Looking at the prices, it does not matter which way you go. I would take a new rim and spokes and use the hub of the current wheel. I can build wheels but do not have the tools to replace a fork (the headset bearing tools) and this will be cheaper than the fork replacement (for me, my own time costs no money to me though economists will disagree on this).

(02-10-2012, 01:26 PM)Bill Wrote: Okay give a little room for error this morning but anyways there is always the option of looking at different pair of forks? Also some forks come with a post hole at the top to go install some model of these (this link is only an example)..... http://www.amazon.com/SRAM-Force-Brake-Caliper-Set/dp/B002J9FDU2/ .

Again if one has mentioned these then please accept my apologies. Still a little groggy this morning lol.